WASHINGTON – The United States ratcheted up threats against Syria yesterday, warning the regime to stop making “bad choices” such as seeking doomsday weapons, supporting terrorists and helping Saddam Hussein’s agents escape.

Bush administration officials refused to say if military action might be taken, but an official called the warnings “strong shots over the bow” to Syria’s young president, Bashar Assad.

White House press secretary Ari Fleischer called Syria a “rogue nation” that has made a series of “bad choices,” like becoming an escape route for Saddam’s fleeing thugs.

“We have information that leaders have crossed the border, people who are important,” Fleischer said. “Syria needs to cooperate.”

Secretary of State Colin Powell said the administration will “examine possible measures of diplomatic, economic or other nature” if the Syrians don’t get in gear.

“We believe in light of this new environment, they should review their actions and their behavior,” Powell said.

One big worry is that a stream of Iraqi outcasts could help take control from Assad, who’s considered a weak leader, creating a new regime in Syria made up of ex-Saddam henchmen – and a scenario that would require a military response, officials said.

Defense Secretary Donald Rumsfeld, reciting a list of charges, said, “We have seen a chemical weapons test in Syria over the past 12, 15 months.”

“Second, we have intelligence that shows that Syria has allowed Syrians and others to come across the border into Iraq, people armed, people carrying leaflets indicating that they’ll be rewarded if they kill Americans and members of the coalition.”

“And we have intelligence that indicates that some Iraqi people have been allowed into Syria, in some cases to stay, in some cases to transit,” Rumsfeld added.

Asked if he was sending a signal that, after Iraq, the Syrians are next on the hit list, Rumsfeld said, “I didn’t say anything like that. I’ve said what I said. I’ve stated facts. In terms of policy, that’s for others.”

The CIA says in a just-released report that Syria has a stockpile of the nerve agent sarin and has sought precursors and expertise for chemical weapons from foreign sources. Syria has received missile technology from North Korea and Russia, the agency says.

British Foreign Secretary Jack Straw advised Syria to cooperate and answer questions about its weapons and whom it’s harboring, but he added, “We have made it clear that there are no plans for Syria to be next on the list.”

Syrian officials called the charges lies and “disinformation.”

“Israel is the only state in the region that has nuclear, chemical and biological weapons,” said Syria’s deputy U.N. ambassador, Fayssal Mekdad. “We did not give any facilities for Iraqis running away, and this is our position.”